aboutsummaryrefslogtreecommitdiff
path: root/kernel/events
diff options
context:
space:
mode:
authorAndi Kleen <ak@linux.intel.com>2013-01-24 16:10:28 +0100
committerArnaldo Carvalho de Melo <acme@redhat.com>2013-04-01 12:15:44 -0300
commitc3feedf2aaf9ac8bad6f19f5d21e4ee0b4b87e9c (patch)
treefb383d4c8037d476b52c424a0a51b1e3c3c7614f /kernel/events
parent9fac2cf316b070ae43d2ae2525e381ff2d1d68aa (diff)
downloadvexpress-lsk-c3feedf2aaf9ac8bad6f19f5d21e4ee0b4b87e9c.tar.gz
perf/core: Add weighted samples
For some events it's useful to weight sample with a hardware provided number. This expresses how expensive the action the sample represent was. This allows the profiler to scale the samples to be more informative to the programmer. There is already the period which is used similarly, but it means something different, so I chose to not overload it. Instead a new sample type for WEIGHT is added. Can be used for multiple things. Initially it is used for TSX abort costs and profiling by memory latencies (so to make expensive load appear higher up in the histograms). The concept is quite generic and can be extended to many other kinds of events or architectures, as long as the hardware provides suitable auxillary values. In principle it could be also used for software tracepoints. This adds the generic glue. A new optional sample format for a 64-bit weight value. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: acme@redhat.com Cc: jolsa@redhat.com Cc: namhyung.kim@lge.com Link: http://lkml.kernel.org/r/1359040242-8269-5-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7b4a55d41ef..9e3edb272b3 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -976,6 +976,9 @@ static void perf_event__header_size(struct perf_event *event)
if (sample_type & PERF_SAMPLE_PERIOD)
size += sizeof(data->period);
+ if (sample_type & PERF_SAMPLE_WEIGHT)
+ size += sizeof(data->weight);
+
if (sample_type & PERF_SAMPLE_READ)
size += event->read_size;
@@ -4193,6 +4196,9 @@ void perf_output_sample(struct perf_output_handle *handle,
perf_output_sample_ustack(handle,
data->stack_user_size,
data->regs_user.regs);
+
+ if (sample_type & PERF_SAMPLE_WEIGHT)
+ perf_output_put(handle, data->weight);
}
void perf_prepare_sample(struct perf_event_header *header,